/*
 * Codegen for `traverse`.
 *
 * Parses Rust AST type definitions from files in `crates/oxc_ast/src/ast`, and generates:
 * - `src/traverse.rs`
 * - `src/ancestor.rs`
 * - `src/walk.rs`
 *
 * This is a quick-and-dirty version written in JS for speed of implementation.
 * We should do this properly with a Rust build script using `syn` etc.
 */

import { exec } from 'child_process';
import { writeFile } from 'fs/promises';
import { join as pathJoin } from 'path';
import { fileURLToPath } from 'url';
import { promisify } from 'util';
import generateAncestorsCode from './lib/ancestor.mjs';
import getTypesFromCode from './lib/parse.mjs';
import generateTraverseTraitCode from './lib/traverse.mjs';
import generateWalkFunctionsCode from './lib/walk.mjs';

const execAsync = promisify(exec);

const PREAMBLE = '// Auto-generated code, DO NOT EDIT DIRECTLY!\n' +
  '// Generated by `oxc_traverse/scripts/build.mjs`.\n' +
  '// To alter this generated file you have to edit the codegen.\n\n';

const types = await getTypesFromCode();

const outputDirPath = pathJoin(fileURLToPath(import.meta.url), '../../src/generated');

await Promise.all([
  writeToFile('traverse.rs', generateTraverseTraitCode(types)),
  writeToFile('ancestor.rs', generateAncestorsCode(types)),
  writeToFile('walk.rs', generateWalkFunctionsCode(types)),
]);

/**
 * @param {string} filename
 * @param {string} code
 */
async function writeToFile(filename, code) {
  code = `${PREAMBLE}${code}`;
  const path = pathJoin(outputDirPath, filename);
  console.log('Writing:', path);
  await writeFile(path, code);
  await execAsync(`rustfmt ${JSON.stringify(path)}`);
}
